[Axel Sostre]

Hello everyone, looking for some insight into my problem with my 160k mile 2013 F30 335i, specs on the car: Catless DP, Upgraded Intercooler, stage 1 tune, and Muffler delete.

Now to the problem, around 2.5 weeks ago, I was driving on the highway at highway speeds 65 mi/hr. I noticed that whenever I would let go of the throttle, there was a subtle jolt, not even my passenger at the time could feel it but I did somehow. I drive for an additional five minutes like that until I get to my exit. Of course their was a red light, so I slowed down, reached a standstill, and then the car started to go up and down in revs crazy, as if it was misfiring, and then it turned off. I go crank the car and nothing, again, nothing. Then I called one of my friends to come pick me up because I was 5 minutes from my house. He arrives, and he says, "let me try and turn it on"(at this point, it's been sitting for 15 mins). So he does crank it, and it turns on. I tell him to drive it home and give me his keys so I can get back. He drives it back the 5 mins, essentially jolting badly whenever he got near 0 mi/hr speeds. We get back and talk about it. We just thought, maybe its a fuel issue, no biggie. But it's ticking now at idle. So I decide to not drive it anymore or turn it on.

Next day I don't know what urged me to open my oil cap and check my filter and PICTURE's 1 and 2 is what I see. To me I immediately think Oil Filter Housing Gaskets failed. So I called the dealership the next day and setup an appointment, mind you its the BMW of Downtown Denver so it's the only one near 10 mins outside of the main city so I have no other options.

I call and they say ok bring it in. I tow it in on February 11th, 2026 at around 8am. I get their drop it off and get a loaner. I specifically tell the advisor that it is the OFHG but I still want to conduct a diagnostic to make sure it may not be something else.

Feb. 12th,2026. I get a phone call, "Ok, so we performed a diagnostic test and found that your Valvtronic motor and shaft and harness failed" price: $5071.44. I immediately am shook for all the good reasons after hearing that number and something that does not address my problem of the oil being contaminated. I then ask them to do other tests because I cannot believe it. She replies that 3 technicians, including the lead tech, have looked at the oil and said that it is just Moisture in the Oil. We argue a bit and then they said that they would perform a coolant pressure test to see if it is leaking into the oil. I ask them to do that and perform another oil change to make sure that for sure it is not the OFHG's.

Couple days later they call, and they say that the car passed the test but after performing the Oil change. The color of the oil changed again even worse than the 2nd picture, It looked like mud, suspecting that my theory was right that the OFHG was bad and contaminating the oil. Just like I thought and told them at the beginning. So they tell that they will fix the OFHG gaskets and perform another oil change and do a coolant flush. So I approve the estimate for $2,025.

Feb 12th, 2026 The next day I get a message stating this, "The technician is currently working on your vehicle. He said your OFHGs do not seem to be old or worn. Have you recently had the OFH resealed?". I answer, since I have owned the car no one has messed or replaced anything near the OFHG except the Oil filter when I do oil changes. At this point I am getting fed up with going back and forth not knowing what is wrong with the car.

Feb 14th, 2026, they get back to me saying that they fixed everything and performed a road test and a drivetrain malfunction came up relating to the Vanos Solenoids getting stuck which they said is most likely caused by coolant contaminating them. They said they would clean them and do another test again. So I leave them to be.

Feb 18th, 2026- Now it's been a long time and I am expecting my car anytime. They text me saying that the their are no more drivetrain malfunctions and confirmed that their are is no more coolant leaking into the oil.

Feb 19th, 2026- I go and pick up my vehicle and the start up is funny like it is struggling but I don't think much of it. I drive off back to my house 30 mins and go to class because I am in College still. Then VIDEO #1 is the cold start after my class. Mind you this is 4 hours after initially picking the car up. And it starts like crap. I have the GTS roar tuned and it is not doing it to this day. I immediately think something is wrong for sure. I have my internship which is like 30 minutes from the house, so I drive it because the car is fine at driving speeds.

Feb 20th, 2026- I do not drive the car at all

Feb 21st, 2026- I drive it to go see my freinds and get dinner with them and everything is fine until I am 3 minutes from my house again and I give it gas and VIDEO #2 you can see that I only get 120HP from the graph even after the throttle is all the way down. Mind you its been less than 100 miles that I have driven the car by this point. That same day I do some research as to why that can happen and I stumble upon ignition coils. I take them out and clean them myself and inspect them as well. I noticed that cylinder towards the back had worse seals than the front. I put them back and go on a drive and then I get a drivetrain malfunction, I scan the car with a scanner and get codes P300, P304, P305. Meaning misfires in cylinders 4 and 5. I end up going to a gas station and check the oil again and PICTURES 4 and 5/ LAST 2 PICS are what I saw. The oil looks contaminated and more watery than I would assume it would. FYI they put 0W-30 LLo1FE instead of the oil I normally put which is Liqui Moly 5W-30 LLo1. I don't know if it is supposed to look like that watery. Please let me know.

From their I swapped coils from cylinder's 4 and 5 to cylinders 1 and 2 and cleared codes. I started it up and it was amazing; it was sounding healthy again. I drove it home and let it sit again.

Feb 22nd, 2026- I ordered new Turner Motosports Performance Ignition coils. ALL 6.

Feb 23rd, 2026- Today, I was curious again to see how the car would sound after sitting for a whole day. AAAAANNNDDDDD it started ticking like it did when I blew my OFHG. SOOOO, what do yall think, Should I call the dealer and complain or perform another oil change myself. I am lost for ideas but I believe that this should be something they have to fix becuase the Oil should not look like that at all to me. Its too watery.

[oceanview]

If water was in the oil, a simple oilchange won't be enough. You sitll have old oil in the oilcooler and the hoses. So it could be leftover old "oil-water" that got mixed with the new oil.
Did they flush the oil system and check the new oil after a few minutes/hours of running for it's quality?

However I would not start the engine anymore with such an oil and first do an oil and filter change, have the oil cooler and the oil hoses flushed. Then start the engine again an proper failure analysis.

If the water cooling system is draining water into the engine oil, you should normally see that the water level goes down significantly.
Having such an oil is not just because there is a bit of moisture in the oil that will gas off after an extended ride! (That's my opinon)

Is the cooling water level stable, or does/didi it go down (like from Max to Min mark)?

For sure something for a porfessional shop to make a clear analysis before riding again.